Thermal,swelling and stability kinetics of chitosan based semi-interpenetrating network hydrogels     

Muhammad Omer Aijaz  Sajjad Haider  Fahad S. Al-Mubaddel  Rawaiz Khan  Adnan Haider  Abdulaziz Abdullah Alghyamah  Waheed A. Almasry  Mohammad Sherjeel Javed Khan  Muhammad Javid  Wajahat Ur Rehman 《Fibers and Polymers》2017,18(4):611-618

The present study is focused on studying the swelling kinetics, thermal and aqueous stabilities, and determination of various forms of water in the chitosan (CS) and polyacrylonitrile (PAN) blend and semi-interpenetrating polymer network (sIPN). CS/PAN blend hydrogel films were prepared by solution casting technique. The blend film with optimum swelling properties was selected for the synthesis of sIPN. CS in the blend was crosslinked with the vapors of Glutaraldehyde (GTA) to prepare sIPN. The fabricated CS/PAN blend and sIPN hydrogels films were characterized with Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and field emission scanning electron microscope (FESEM). The kinetics of swelling, bound and unbound waters and aqueous stability were determined experimentally. FESEM showed good miscibility between CS and PAN, FTIR showed no chemical interaction between CS and PAN; however, it did show a doublet for the sIPN, TGA showed improved thermal stability and swelling kinetic followed second order kinetics. The degree of swelling of the sIPN hydrogels samples at room temperature varied from ~2200 % (with a fair degree of stability (~30 %)) to ~1000 % (with high degree of aqueous stability (43 %)) with increase in the crosslinking time. The calculated unbound water (W_UB) max., for the blend was 52.3 % whereas for the bound (W_B) the max., was 41.9 %. However, for sIPN hydrogel films, the W_UB water decreased (max. 21.0 %) where as the W_B increased (max. 52.0 %). The decrease in W_UB and increase in the W_B is attributed to the formation of a compact structure and increase in the contact area between the water and polymers in sIPN hydrogels due to the induction of new water contacting point in these hydrogel films, respectively.  相似文献   

Comparison of three serological tests in the diagnosis of Brucella infection in unvaccinated cattle in Eritrea     

Omer MK  Skjerve E  MacMillan AP  Woldehiwet Z 《Preventive veterinary medicine》2001,48(3):215-222

Three serological methods, the Rose-Bengal test (RBT), the complement-fixation test (CFT) and an indirect enzyme-linked immunosorbent assay (I-ELISA) were compared for the detection of Brucella-infected animals in unvaccinated cattle herds in Eritrea. In this study, 71 herds first were classified as positive or negative for Brucella infection on the basis of at least one animal being seropositive by RBT and CFT. All the 159 RBT-positive samples from the 26 seropositive herds and 214 RBT-negative samples randomly selected from the seropositive herds and from the 45 negative herds were tested further by CFT and I-ELISA. Using the ELISA titer as main predictor, and incorporating the RBT results, a logistic model was built to predict the CFT-negative or -positive status of individual sera and to estimate sensitivity and specificity. Whilst the ELISA titers (< or =20) accurately predicted all the negative sera in herds that were also negative by the CFT, the number of seropositive animals was higher by ELISA in herds that had positive animals. Serum samples which give higher degrees of agglutination with the RBT need not be re-tested with CFT; consideration of the seropositive status of a herd should be taken into consideration on defining the cut-off optical density readings for ELISA.  相似文献   

Association between insecticide use and greenhouse whitefly (Trialeurodes vaporariorum westwood) resistance to insecticides in hawaii     

Amir D. Omer  Marshall W. Johnson  Bruce E. Tabashnik  Diane E. Ullman 《Pest management science》1993,37(3):253-259

Susceptibility to acephate, methomyl, and permethrin was determined with laboratory bioassays for adults of greenhouse whitefly, Trialeurodes vaporariorum Westwood, from 12 to 14 sites in Hawaii. Comparisons at LC₅₀ showed up to 42-fold resistance to acephate, 36-fold resistance to methomyl, and 8-fold resistance to permethrin. Higher levels of resistance to acephate and methomyl than to permethrin are consistent with greater use of organophosphates and carbamates than pyrethroids by growers. Insecticide use varied from 1 to 98 insecticide sprays per site per season. Significant positive associations between LC₅₀ for each insecticide and frequency of application of the same insecticide were found across sites. This finding suggests that local variation in insecticide use was an important cause of variation in susceptibility.  相似文献   

Essential oil composition and antioxidant activity of endemic Ziziphora taurica subsp. cleonioides     

Meral GE  Konyalioglu S  Ozturk B 《Fitoterapia》2002,73(7-8):716-718

The essential oil of Turkish endemic Ziziphora taurica subsp. cleonioides aerial parts was found to contain (+)-pulegone (81.86%), limonene (4.48%) and piperitenone (2.30%) activity. The essential oil showed relevant antioxidant activity.  相似文献   

Effect of essential oils of some medicinal plants on phytonematodes     

Mahfouz M. Abd-Elgawad  Elsayed A. Omer 《Journal of pest science》1995,68(4):82-84

The essential oils of four medicinal plants belonging to Lamiaceae were explored for phytonematode control. The four oils inhibited (P<0.05) nematode motility butMentba spicata was generally more effective in reducing the numbers of active nematodes followed byThymus vulgaris, Majorana bortensis andMentba longifolia. The main corresponding compound of each oil, determined by GLC analysis, was carvone (58.14%), P-cymene (40.5%), terpinen-4-ol (41.6%) and carvone (70.36%). Soil stages of the reniform nematode were more affected by the oil than those of the ring and lance nematodes. When transferred to water, the total nematodes that regained their activeness ranged from 12% forT. vulgaris to 60% forM. longifolia. The four 0.1 oil solutions inhibited more than to about 3.5% at the control. The content of oxygenated compounds in these oils ranged from 45.79% to 96.5% and may be partially responsible for the nematicidal effects.  相似文献   

Electrical stimulation of lumbar spinal nerve roots in dogs     

Erkut Turan  Cengiz Unsal  Mehmet Utkan Oren  Omer Gurkan Dilek  Ismail Gokce Yildirim  Murat Sarierler 《Veterinary research communications》2014,38(3):229-235

The aim of this study was to test the applicability of electrical stimulation of lumbar spinal nerve roots and obtain normative electrical root stimulation (ERS) data for L7 nerve root and sciatic nerve in dogs. For that purpose ERS and sciatic nerve stimulations were performed consecutively, in totally 40 healthy dogs. ERS was applied in the L7/S1 intervertebral space via monopolar needle electrodes. Muscle responses were recorded from the gastrocnemius muscles on the left and right hind limbs. Sciatic nerve stimulation was performed at the greater trochanter level on the left hind limb, with records obtained from the left gastrocnemius muscle. Mean root latencies of the left and right side were 5.22?±?0.49 ms and 5.29?±?0.53 ms, respectively. There was no significant difference in root latency between the right and left sides. The mean terminal latency was 3.82?±?0.46 ms. The proximal motor nerve conduction velocity of the sciatic nerve was 63.15?±?3.43 m/s. The results of this study show that ERS provides objective data about the integrity of lumbar spinal nerve roots by evaluating the entire population of motor fibres and total length of the motor axon in dogs. ERS can be considered a useful diagnostic method for confirmation of diagnoses of lumbosacral diseases.  相似文献   

Risk factors for occupational brucellosis among veterinary personnel in Turkey     

Murat Kutlu  Onder Ergonul  Selda Sayin-Kutlu  Tumer Guven  Cemal Ustun  Sema Alp-Cavus  Serife Barcın Ozturk  Ozlem Acicbe  Serife Akalin  Recep Tekin  Suda Tekin-Koruk  Yusuf Ziya Demiroglu  Ramazan Keskiner  Ibak Gönen  Sevil Sapmaz-Karabag  Vuslat Bosnak  Esra Kazak 《Preventive veterinary medicine》2014

Veterinarians and veterinary technicians are at risk for occupational brucellosis. We described the risk factors of occupational brucellosis among veterinary personnel in Turkey. A multicenter retrospective survey was performed among veterinary personnel who were actively working in the field. Of 712 veterinary personnel, 84 (11.8%) had occupational brucellosis. The median number of years since graduation was 7 (interquartile ranges [IQR], 4–11) years in the occupational brucellosis group, whereas this number was 9 (IQR, 4–16) years in the non-brucellosis group (p < 0.001). In multivariable analysis, working in the private sector (odds ratio [OR], 2.8; 95% confidence interval [95% CI], 1.55–5.28, p = 0.001), being male (OR, 4.5; 95% CI, 1.05–18.84, p = 0.041), number of performed deliveries (OR, 1.01; 95% CI, 1.002–1.02, p = 0.014), and injury during Brucella vaccine administration (OR, 5.4; 95% CI, 3.16–9.3, p < 0.001) were found to be risk factors for occupational brucellosis. We suggest that all veterinary personnel should be trained on brucellosis and the importance of using personal protective equipment in order to avoid this infection.  相似文献   

Personality Characteristics in a Population of Mountain Climbers     

Erik Monasterio  Yassar A. Alamri  Omer Mei-Dan 《The Forestry Chronicle》2014,25(2):214-219

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Some Physicochemical Characteristics,Bioactive Content and Antioxidant Characteristics of Non-Sprayed Barberry (Berberis vulgaris L.) Fruits from Turkey     

Hilal Yildiz  Sezai Ercisli  Memnune Sengul  Elif Feyza Topdas  Omer Beyhan  Ozlem Cakir  Haluk Kemal Narmanlioglu  Emine Orhan 《Erwerbs-Obstbau》2014,56(4):123-129

Increasing consumer demands for indigenous, non-sprayed with pesticides and less-known or “forgotten” fruits necessitate knowledge on their breeding, cultivation, biochemical content, harvesting and marketing. Anatolia is rich for wild edible fruit species and barberry is abundant throughout Anatolia. The aim of this study was to determine some important physicochemical characteristics, bioactive content and antioxidant capacity of fruits from nineteen promising barberry (Berberis vulgaris L.) genotypes grown in the Coruh valley, Northeastern Anatolia. The results indicated genotype-specific differences for most of the physicochemical characteristics, antioxidant capacity and the content of some bioactive compounds. Fruit mass ranged from 0.073 (‘Coruh-7’) to 0.267 g (‘Coruh-11’). Total phenolic content ranged from 2532 (‘Coruh-’) to 3719 mg GAE per liter fruit juice (‘Coruh-11’). The genotype ‘Coruh-12’ had the highest total monomeric anthocyanin content (1004 mg per liter fruit juice) as cyanidin-3-glucoside. The highest total antioxidant capacity was observed in fruits of ‘Coruh-8’ and ‘Coruh-9’ genotypes with all three antioxidant-determining methods. We conclude that the barberry fruits represent a good source of bioactive phytochemicals because of their high phenolic and anthocyanin contents.  相似文献   

Effect of Water Stress at Various Growth Stages on Some Quality Characteristics of Winter Wheat   总被引：8，自引：0，他引：8  

A. Ozturk  F. Aydin 《Journal of Agronomy and Crop Science》2004,190(2):93-99

A field experiment was carried out in Erzurum (Turkey) on winter wheat to analyse the effect of water stress at different growth stages – fully irrigated (FI), rainfed (R), early water stress (EWS), late water stress (LWS) and continuous water stress (CWS), on some quality characteristics – in the 1995–96 and 1996–97 cropping seasons. Water stress had a substantial effect on most of the quality characteristics. As averages of cropping seasons, CWS, EWS, R and LWS treatments decreased grain yields by 65.5, 40.6, 30.5 and 24.0 %, respectively, compared with the FI treatment. CWS increased grain protein content by 18.1 %, sedimentation volume by 16.5 %, wet gluten content by 21.9 % and decreased 1000‐kernel weight by 7.5 g compared with FI treatment. LWS caused an increase of 8.3 % in grain protein content, 8.7 % in sedimentation volume, 10.8 % in wet gluten content and a reduction of 3.8 g in 1000‐kernel weight compared with FI. EWS and R increased sedimentation volume and wet gluten content, but decreased 1000‐kernel weight compared with FI. The effect of LWS on grain quality was more significant than that of EWS. The results suggest that soil moisture conditions increase grain yield and kernel weight of winter wheat but decrease its quality.  相似文献